When AES(☢) = ☠ – a crypto-binary trick
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When AES(☢) = ☠ – a crypto-binary trick
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Re: When AES(☢) = ☠ – a crypto-binary trick
#2Re: When AES(☢) = ☠ – a crypto-binary trick
#3impressive! a very cool hack!
Re: When AES(☢) = ☠ – a crypto-binary trick
#4A good example of why a MAC after encryption is also needed. And blocking length extension attacks.
Re: When AES(☢) = ☠ – a crypto-binary trick
#5Cool trick, I have encountered something like this in a steganography wargame before, the only difference is they used Base64 encoding on the original picture instead of AES :)
Re: When AES(☢) = ☠ – a crypto-binary trick
#6Recording of the talk: http://podcast.raumzeitlabor.de/#wbHkVZfCNuE
Re: When AES(☢) = ☠ – a crypto-binary trick
#7Impressive.
That's also the reason why one should limit the max-length of a password field (something reasonable), if one is using the salted-password in db approach. Otherwise someone could enter a very long password to do the trick (MD5/SHA1), see http://en.wikipedia.org/wiki/MD5#Security .
Re: When AES(☢) = ☠ – a crypto-binary trick
#8Impressive. That's also the reason why one should limit the max-length of a password field (something reasonable), if one is using the salted-password in db approach. Otherwise someone could enter a very long password to do the trick (MD5/SHA1), see http://en.wikipedia.org/wiki/MD5#Security .
I guess I'm not following your logic. If there is a salted, hashed password in a db, allowing arbitrary length passwords shouldn't matter? HMACs and KDFs work very differently from symetric-crypto primatives.
Re: When AES(☢) = ☠ – a crypto-binary trick
#9Impressive. That's also the reason why one should limit the max-length of a password field (something reasonable), if one is using the salted-password in db approach. Otherwise someone could enter a very long password to do the trick (MD5/SHA1), see http://en.wikipedia.org/wiki/MD5#Security .
I guess I'm not following your logic. If there is a salted, hashed password in a db, allowing arbitrary length passwords shouldn't matter? HMACs and KDFs work very differently from symetric-crypto primatives.
The point is that it makes it easier for an attacker to find a hash collision. It's much easier to construct data which hashes to a given value if it can be of arbitrary length. I don't immediately see the connection with this article however.
Re: When AES(☢) = ☠ – a crypto-binary trick
#10Earlier quoted context omitted.
I guess I'm not following your logic. If there is a salted, hashed password in a db, allowing arbitrary length passwords shouldn't matter? HMACs and KDFs work very differently from symetric-crypto primatives.
The point is that it makes it easier for an attacker to find a hash collision. It's much easier to construct data which hashes to a given value if it can be of arbitrary length. I don't immediately see the connection with this article however.
The attacker doesn't need a hash collision in the case you're describing; they need a preimage.